[ale] Setting up a large wifi environment....

[Jim Kinney]

Take total user count and multiply by the estimate of the lowest
acceptable bandwidth per user. Assume a max throughput of any 802.11b
AP to be at 70% of theoretical max (30% loss due to collisions and
distance/signal strength issues). Divide first number by second and
round up to get a minimum number of AP's.

total users * acceptable bps/( .7 * 11Mbps)

Join all AP's with 100Mbps to a single switch with the gateway system
also on the switch.

Physical placement is an engineering challenge. You want overlapping
coverage so no dead spots but not greatly overlapping to avoid hot
spot swapping and to use as few AP's as possible. Signal attenuation
through materials is a challenge as well. A plain sheetrock wall has a
small signal loss. But add a bit of vertical-run wiring and the effect
is much greater. Add a bundle of plumbing AND wiring and you've got a
dead spot. Plaster walls with metal lathe will act more like a Faraday
cage than anything else. Microwave ovens wreak havoc with
802.11a/b/g/n so kitchen areas will be fun. Plus all the metal will
kill of the signal anyway. New concrete block walls are not a
shielding as old concrete block walls. Schools with tile over concrete
block are nearly nuclear weapon proof. A WAP in the hall will have
almost no signal in the adjacent room unless the receiver is near the
doorway.

On Sat, May 16, 2009 at 7:43 PM, Jim Popovitch <jimpop at gmail.com> wrote:
> Hi all,
>
> I'm looking for some feedback on setting up a large (~200 user)
> *temporary* wifi network on the cheap.  Ideally i would like to do
> this with off-the-shelf linksys/belkin/d-link/etc gear.   I imagine
> that it will take several APs, but I'm not sure how many nor how to
> calculate how many.   This will be a wide-open 802.11b network and I'm
> only specifically looking for info on the physical implementation of
> such a network.
>
> Thanks!
>
> -Jim P.
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> Ale at ale.org
> http://mail.ale.org/mailman/listinfo/ale
>



-- 
-- 
James P. Kinney III
Actively in pursuit of Life, Liberty and Happiness